There are several videos like this online, most bogus, as this one seems to be. It looks staged but it is interesting that the eagle tried to carry such a heavy weight. It looks like it couldn’t get lift so it dropped it.
As near as I can tell, the ‘deer’ looks to be a chamois in the alps.
Speaking of deer, I just saw a doe and three fawns evenly spaced about 10 yards apart cross the road. It was really cute.
Well it was dead to start with well before the eagle picked it up, so it does not really show much. Plus, that kind of shot from behind a flying eagle swooping down, that cannot just be a lucky break, the staging is in leaving a dead chamois someplace the eagle can find it, coming from an easy to predict angle.